The present invention relates to an electroluminescence display device.
As a new type of display device, electroluminescence (EL) display device displays by using light generated through electrically exciting organic compounds. The EL display device has advantages of low power consumption, flat plate display, self-illuminating, etc. However, due to insufficient performance and being heated intrinsically in operation, the organic compounds developed currently have a short lifetime. Typically, red and green organic compounds for emitting red and green color light respectively have a lifetime more than about 40,000 hours, and blue organic compound for emitting blue color light has a shorter lifetime of about 10,000-15,000 hours, which is about ⅓ of that of the red and green organic compounds, since the blue organic compound is heated more quickly.
As described above, since the red, green and blue organic compounds constituting an EL display device have different lifetimes, and in particular, the lifetime of the blue organic compound is about ⅓ of that of the red and green organic compounds, the blue organic compound render decreased the lifetime of the whole EL display panel using such three kinds of organic compounds.
Two technical solutions to extend the lifetime of blue sub-pixels have been proposed in a conventional technology. One is to apply a low electrical current to a blue sub-pixel, and the other is to enlarge area of the blue sub-pixel while applying a low electrical current thereto. Although the first method of applying a low electrical current may extend the lifetime of blue sub-pixels, color reproduction under a low current is weaker than that under a normal electrical current, and thus color requirement for full color display can not be satisfied properly. The second method satisfies a general color requirement by enlarging the area, but the color reproduction is still weaker than that that under a normal electrical current and the color requirement for full color display cannot be satisfied either.